Electrolytic machining and fixturing means

ABSTRACT

A FIXTURING ARANGEMENT UTILIZED IN THE ELECTROLYTIC MACHINING OF SHAPES FROM BAR STOCK HAVING A PAIR OF COOLING CHAMBERS DISPOSED ON OPPOISTE SIDES OF AN ELETROLYTE CONTAINING CHAMBER. EXPANDABLE SEALING MEANS ARE DISPOSED BETWEEN THE COOLING CHAMBERS AND ELECTROLYTE CONTAINING CHAMBER AND SEALIG MEANS ARE ALSO DISPOSED AT THE ENDS OF THE COOLING CHAMBERS REMOTE FROM THE ELECTROYLTE CONTAINING CHAMBER. THE SEALING MEANS ENVELOP THE BAR STOCK PERMITTING IT TO EXTEND THROUGH AND BE MOVABLY INDEXED WITHIN THE COOLING AND ELECTROLYTE CONTAINING CHAMBERS. A GUIDANCE AND ALIGNMENT MEANS HAVING NON-INTERFERING MACHINING ELECTRODE CHARACTERISTIC IS ALSO INCLUDED WITHIN THE ELCETROLYTE CONTAINING CHAMBER TO PROVIDE GUIDANCE AND SUPPORT FOR THE POSITION OF THE BAR STOCK THEREWITHIN.

Jan. 12, 1971 ELP, scHELLENs ETAI- 3,554,392

ELECTROLYTIC MACHINING AAND FIXT-URING MEANS Filed Feb. 27. 1967 4SheetS-Sheet l SR. mmJ. oLK

P HPC@ mm w W m# m Q @Il rL l Nv vm om /Lmm \.TW www mm ATTORNEYS Jan.12, 1971 E, P, SCHELLENS ETAL 3,554,892

ELECTROLYTC MACHINING AND FIXTURING MEANS Filed Feb. 27. 1967 4Sheets-sheet z M fw ATTORNEYS Jari. 12; 1971 E' P, SCHELLENS ETAL3,554,892

ELECTROLYTIC MACHINING AND FIXTURING MEANS INVENTORS EUGENE P. SCHELLENSATTORNEYS Jan. 12., 1971 E, p SCHELLENS ETAL 3,554,892

l -ELECTROLYTIC MACHINING AND FIXTURINGYMEANS Filed Feb. 27. 196'? 4Sheets-Sheet 4 u. K l n ijs? .IV /Y FIG. a

- INVE ORS EUGENE P. SCH LENS.

ROY E. BLACK,JR Fla-9 Mm.

ATTORNEYS United States Patent Office Patented Jan. 12, 1971 U.S. Cl.204-206 Claims ABSTRACT OF THE DISCLOSURE A fixturing arrangementutilized in the electrolytic machining of shapes from bar stock having apair of cooling chambers disposed on opposite sides of an electrolytecontaining chamber. Expandable sealing means are disposed between thecooling chambers and electrolyte containing chamber and sealing meansare also disposed at the ends of the cooling chambers remote from theelectrolyte containing chamber. The sealing means envelop the bar stockpermitting it to extend through and be movably indexed within thecooling and electrolyte containing chambers. A guidance and alignmentmeans having non-interfering machining electrode characteristics is alsoincluded within the electrolyte containing chamber to provide guidanceand support for the position of the bar stock therewithin.

Although apparatus utilizing the electrolytic principle for the removalof material and thereby the shaping of intricate, difficult to machineparts is known, none of these prior art devices have provided a highproduction output and none of these machines have functioned to providea direct line sequential output. Such an operative arrangement wouldmaterially reduce the time required for the production of these parts,such as turbine blades, by reducing handling and feed time of theseparts from and to the electrolyte machining operation to thereby reducethe cost of the produced parts to a minimum. It would, therefore, bedesirable to provide a direct line production apparatus utilizing theelectrolytic removal principle which not only provided a high productionrate but also furnished a product whose dimensions and quality could beclosely controlled.

Accordingly, it is an object of the invention to provide an apparatusfor electrolytically shaping parts including the fixturing therefor, theapparatus having a direct line feed and, therefore, high production.

It is an additional object of the invention to provide the fixturing foran electrolytic apparatus so that product parts may be sequentiallyformed along the length of bar or strip stock.

It is an additional object of the invention to provide a fixturing forthe bar or strip stock that insures proper cooling thereof under thehigh current rates utilized in the electrolytic shaping of theproduction items, such as turbine blades and the like.

It is a further object of the invention to provide a positive sealingmeans which permits sequential movement of the bar or strip stockthrough the fixturing and also prevents leakage of the electrolyte andcoolant outwardly of the fixturing or into an interminglingrelationship.

It is an additional object of the invention to provide for positivealignment of the bar or strip stock contacting electrodes to insureintimate contact therebetween and proper conducting of the anodeelectrical current away from the fixturing.

It is a still further object of the invention to provide an insulatingbarrier between the fixturing so that the coolant in that portion of thefixturing is at bar or strip stock potential.

Cil

It is still a further object of this invention to provide a variablespacing means in the fixturing to accommodate variable length productionturbine blades or the like.

It is a still further object of the invention to positively guide thebar or strip stock within the fixturing which still permits rapid andproper electrolytic machining to occur.

Other and further objects of the invention will be apparent from thefollowing description and claims and may be understood by reference tothe accompanying drawings which, by way of illustration, show apreferred embodiment of the invention and what is to be considered tolbe the best mode for applying the above principles.

In the preferred embodiment of the invention a pair of sealed coolingfixtures are disposed on opposite sides of a sealed fixture chambercontaining the electrolyte and cathode electrodes, these electrodesbeing provided with the opposite shape as that desired of the finallyfinished piece. Each of the sealed cooling fixtures contains a pair ofelectrodes in contact with the bar or strip stock to serve as a currentcarrier for it, provisions being made by electrode mounting means toinsure that there is intimate contact between the electrodes andworkpiece. A sealingfmeans is provided at each end of each of thecooling fixtures to prevent the escape of coolant therefrom andthe'intrusion of electrolyte into the cooling fixtures or outwardly toatmosphere from the central fixture electrolyte containing chamber. Thebar or strip stock from which the turbine blades or the like areelectrolytically machined extends through the cooling fixtures andcentral fixture chamber with the electrolyte machining apparatus havingan indexing means for moving the bar or strip stock the amount requiredto bring unmachined material into the chamber after a single blade orthe like has been formed on a preceding portion of the bar or stripstock. The sealing means, previously described, provides for movement ofthe bar or strip stock during this indexing operation. Guide means arealso provided within the central fixture electrolytic chamber to insureproper alignment of the bar or strip stock so that the cathodes of theelectrolytic machining apparatus move uniformly towards the bar or stripstock on opposite sides thereof.

A better understanding of the invention will be had with reference tothe appended drawings wherein:

FIG. 1 is a view of the entire device taken generally along line 1 1 ofFIG. 2, but shown only partly in crosssection;

FIG. 2 is across-sectional view of a portion of the device shown in FIG.l taken along line 2 2 of FIG. l;

FLIG. 3 is a cross-sectional View of the inner sealing means and relatedelements as taken generally along line 3 3 of FIG. 4;

FIG. 4 is a cross-sectional view of the inner sealing means and relatedelements taken on line 4 4 of FIG. 3;

FIG. 5 is an enlarged view of the inner sealing means as shown in FIG. l

FIG. 6 is a cross-sectional view of the sealing means taken generally online 6 6 of FIG. 3;

FIG. 7 is a cross-sectional view of the guide means taken generally online 7 7 of FIG. 3;

FIG. 8 is a cross-sectional view of the guide means and locating padtaken on line 8 8 of FIG. 3; and

FIG. 9 is a view in perspective of the lower guide means partly brokenaway.

The invention comprises an electrolytic removal fixturing 10 thatincludes, generally, an electrolyte containing fixture chamber 12located centrally relative to the main body of the electrolytic removalfixturing 10 and a pair of fixture cooling chambers 14 and 16 disposedon opposite sides of the electrolyte containing chamber 12.

Electrolyte containing fixture chamber 12 is partially formed by abottom wall 18 and top wall 19 through which a pair of electrodes and 22of an electrolytic machining apparatus 11 (only partially shown) extendto form the cathode for the electrolytic machining operation, as is seen(FIG. 1). A pair of sidewalls '21 and 23 and a pair of front and backwalls 23A, 23A (only the back wall being shown) complete the chamber 12.The front and back walls 23A, 23A may be attached to the other walls ofthe chamber 12 by any conventional means which insures a sealtherebetween. The electrodes 20` and 22 are oppositely disposed so as tomachine both sides of the portion of a bar stock 24 that extends throughthe electrolytic containing fixture chamber 12 and fixture coolingchambers 14 and 16. Each of the electrodes 20 and 22 is mounted on afeed means 26 that advance or retract the electrodes linearly in aunitary but opposed manner as electrolytic machining of the bar stock 24occurs. A housin-g 28 supports each of the feed means 26 by attachmentof the Ihousings 28 by a series of bolts 29 to the walls 18 and `19,respectively, of the chamber 12. A pair of sealing means 33 and 35 aredisposed between the -feed means 26, the bottom wall 18 or top wall 19and the housing 28 to prevent escape of the electrolyte from bottom ortop area of the electrolyte containing chamber 12. As is conventional inthe art, each of the feed means 26 is preferably controlled by a means(not shown) to advance the electrodes 20 and 22 so that machining of thebar stock 24 occurs in a predetermined and desired manner. An inlet andan outlet means 45 and 47 (FIG. 7) provides, as is conventional, acontinuous flow of high pressure electrolyte solution upwardly betweenthe electrodes 20 and 22, this flow of electrolyte also cooling theportion of bar stock 24 within the electrolyte containing chamber 12.

Each of the fixture cooling chambers 14 and 16 (FIGS. 1 and 2) is agenerally closed container of elongated rectangular configuration with abottom wall 30, top wall 31, side walls 33, 35 and front and back Walls37 and 39, forming, along with an insulating Wall 164, the confines forthe volume of the closed container. Disposed within each of the fixturecooling chambers 14 and 16 are a pair of clamping electrodes 32 and 34that are pivoted on pins 36 and 38 extending from the side 'walls 33 and35 and fixedly supported thereby by outwardly extending fixed pintles41, 41 and 43, 43 to provide a secure pivotal connection for theelectrodes 32 and 34. The clamping electrodes 32 and 34 are eachprovided with a portion 40 that extends rightwardly of the pivot pins 36and 38 (FIG. 2) and which portion 40 is pivoted to a clamping block 42by a pin connection 44 extending loosely through the portion andthreaded into the clamping block 42. An aperture 46 of rectangular shapeprovided in the clamping block 42 permits the portion 40 to extendtherein so that clamping block 42, itself, serves as a trunnion for theportion 40 and connected pivot pin 44. A bore 48 is also provided in theclamping block 42 to provide means for assembly of the pin 44 to theclamping block.

The clamping blocks 42, upon movement of the clamping portions 40, 40towards each other, abut opposite sides of the bar stock 24 and, becauseof their free floating relationship within the chamber 14 or 16, providean intimate electrical contact therewith to positively lead theelectrical current imposed on the bar stock 24 by the electrolyticmachining operation away from it. The electrical current is then ledfrom each clamping block 42 to a pair of cables 50 and 52 that areattached to each of the clamping blocks 42 by a pair of set screws 54,54 threadedly mounted in a pair of bores 56, 56 provided in the clampingblock 42. The cables 50 and 52 seat in a pair of bores 58, 58 providedin the clamping 'block 42 when engaged by the set screws so that both agood physical and electrical connection are provided between the cables50 and 52 and the clamping block 42.

The fixture cooling chambers 14 and 16, at the location of each of thecables 50 and 52, are sealed from atmos phere by a sleeve 53 which isattached to its respective cable by moulding the sleeve around thecable, for example, so as to provide an air and water tight connectiontherebetween. Each sleeve 53 is located on its cable so that it extendsthrough the top or bottom wall 31 or 30, a seal being provided betweenit and the top or bottom wall 31 or 31 by a pair of O-rings 55, 55 whichpermit the sleeve 53 and attached cable to slide without leakage as theclamping electrodes 32 and 34 pivot on pivot pins 36 and 38.

Actuation of the clamping electrodes 32 and 34 is accomplished by adouble acting hydraulic means 60` disposed between the electrodes 32 and34 at the ends thereof opposite the ends 40. The double acting hydraulicmeans 60 is attached to the upper clamping electrode 34 by a pinconnection `61 or the like and is attached to the lower clampingelectrode 32 by a piston 62 of the double acting hydraulic means 60extending downwardly into a bore 64 formed in a boss 66. The boss 66, inturn, is pivotally attached to the clamping electrode 32 by a pin 63extending through a clevis portion 67 of the boss 66. It is evident fromthis arrangement that extension of the piston 62 causes pivoting of theportions 40 of the clamping electrodes 32 and 34 towards each other andmoves the clamping blocks 42 into engagement with the bar stock 24insuring a positive electrical contact therebetween.

In order to permit only limited floating movement of the hydraulic means60 and the adjacent ends of the clamping electrodes 32 and 34 and tolimit downward pivoting of the clamping elctrode 34 due to the force ofgravity a pair of adjustable stops 68 and 70 are provided so as toextend through the walls 30 and 31, respectively, as by being insertedin threaded apertures 73 and 75 therein. These stops are adjusted so asto abut against portions of the clamping electrodes 32 and 34 to providethe foregoing action, A pair of lock nuts 72 and 74 are threadinglyreceived on stops `68 and 70 to insure that these stops may bepositively fixed at the desired position of adjustment.

In View of the large amounts of current that must be passed through thebar stock 24 to obtain a rapid electrolytic machining rate, the fixturecooling chambers 14 and 16 must be supplied with a relatively high flowrate of cooling water. Water flows into each of these chambers throughan inlet to be later described, and exits from the chamber throughoutlet pipes 76 and 78 (shown in phantom in FIG. 2) Which communicatewith the interor of the chamber through the front wall 37. It is, ofcourse, important to keep the water flowing through the cooling chambers14 and 16 relatively pure, especially that water flowing through thefixture cooling chamber 14 since this portion of the flow serves as abath -for the machined bar stock 24 and, therefore, flushes the smallamount of electrolyte remaining on the bar stock from the electrolyticmachining operation. This flushing prevents further uncontrolledelectrolytic machining from occurring in the fixture cooling chamber 14.

A sealing means 80 (FIGS. 1 and 5) is provided on the outward side ofeach of the fixture cooling chambers 14 and 16 to positively prevent theescape of cooling water therefrom and yet to permit indexing of the barstock 24. The sealing means 80 includes a generally oval shaped sealmember 82 with flattened faces on the long sides thereof (incross-section shown in FIG. 6) made of neoprene or the like and having arectangular aperture 83 which extends through a main body portion 81thereof for entrance of the bar stock 24. The seal member 82 thussurrounds the periphery of the bar stock 24 contained therein to providea seal between it and atmosphere and with the remainder of the sealingmeans 80 prevents leakage of cooling water from the cooling chambers 14or 16. A pair of axially spaced first flanges 84, 84 of fairly smallaxial thickness relative to their height extend radially outwardly fromthe main body 8l of the seal member 82 and substantially around one-halfof the pcriphery of the seal member 82. A pair of axially spaced secondtianges 86, 86 projecting from the main body 81 are joined to the firstfianges 84 and extend around the remainder of the periphery of the sealmember 82. The second flanges 86 are of thicker axial dimension than thefirst flanges 84 so that they, in conjunction with the first anges, forma peripheral groove 88 that extends completely around the seal member82, said groove having two different adjoining widths.

A metallic ring member 90, preferably made of stainless steel to resistcorrosion, is seated in and extends entirely around the peripheralgroove 88. Ring member 90 is of substantially the same width as thegrooves 88 and thereby varies in width over its length so as to abutagainst the flanges 84, 84 and the anges 86, 86 within the groove 88 toform a cavity 89 of varying axial dimension between the ring member 90and seal member 82. As will be later explained, the ring member 90limits outward expansion of the seal member 82 upon pressurization anddirects its expanding force into sealing engagement with the bar stock24.

The seal member 82 is disposed within a circular bore 92 forming acavity in an extension 94 of the fixture cooling chamber and abutsinwardly at its inner face 85 against an inner seal retainer 96, thisretainer being mounted within the bore 92 and, in turn, abutting aninner terminatingface 93 thereof. Inner seal retainer 96 is of largerdiameter than seal member 82 and of cylindrical shape so as to extendAradially outwardly of the seal member 82 and is provided with an O-ring98 between its outer periphery and a circumferential wall 99 that formsthe bore 92 to thereby provide a seal therebetween and prevent leakageof cooling water radially outwardly of the Seal member 82. A rectangularaperture 100 with a tapered enlarged portion 101 providing easy entranceof the bar stock 24 extends through the inner seal retainer 96 to permitlinear movement of the bar stock 24 through it. Seal retainer 96 ispreferably made of plastic, such as nylon or the like, so as to serve asan insulator for the bar stock 24.

Surrounding and extending radially outwardly of the seal member 82 andalso disposed within the bore 92 is a. cylindrically shaped seal housingmember 102. This member abuts against inner seal retainer 96 by means ofa shoulder 104 formed thereon and prevents outward movement of the innerseal retainer 96 and also prevents outward movement of the O-ring 98 byabutment therewith by an extension 105 projecting inwardly from the mainportion of the seal housing member 102 A bolt 106 extends axiallythrough the main portion of the seal housing member 102 and the innerseal retainer 96 to compressingly connect the seal housing member 102 tothe extension 94, a depression 107 being provided in the seal housingmember 102 for the purpose of seating the head of bolt 106. A seal isalso formed between the seal housing member 102 and the circumferentialwall 99 forming the bore 92 by an O-ring 108 which is disposed inabutting relation with both of them and seated in an annular groove 109in the seal housing member 102 to provide another outer area of sealingfor the sealing means 80.

A bore 110 of generally attened oval shape in crosssection, extendingaxially and medially in the seal housing member 102, receives the sealmember 82 in a centralized position, radially, to center it so that therectangular aperture 83 of the seal member 82 is aligned with therectangular aperture 100 in the inner seal retainer 96. The bore 110also seats a plastic seal bushing 112 of flattened oval shape incross-section made of nylon or the like to insulate the seal housingmember 102 of the sealing means 80 from the bar stock 24 and center itso that a rectangular aperture 114 extending therethrough is alignedwith the previously related bar stock receiving apertures 83 and 100.

Seal bushing 112 is tightly sealed from seal housing member 102 by anoval shaped sealing ring 116 disposed substantially medially its axialextent in a generally annular groove 117 provided therein so thatanother sealing area is maintained outwardly of the seal member 82. Thelength of the seal bushing 112 is sufiicient to protrude outwardlybeyond the axial extent of the seal housing member 102 so as to be urgedinwardly into engagement with the seal member 82 by a cap member 118 ofdisk shape, the said sealing member 82 being axially compressed by thisarrangement. The cap member 118 tightly holds seal bushing 112 againstthe seal 82 by impingement against an outer face 87 thereof within thebore 110, the cap member 118 being held by a plurality of bolts 113fastening the cap member 118 to the outer end of extension 94. The bolts113 also fasten the extension 94 to its respective fixture coolingchamber 14 or 16.

Means are provided to supply fiuidic pressure to the seal 82 so that it,because of the compressive force applied by the ring member 90, theinner seal retainer 96 and the seal bushing 112, expands inwardly intointimate contact with the bar stock 24 in order that no cooling watercan escape from the fixture cooling chambers 14 or 16. Morespecifically, this means includes a transverse bore 122 having threadstherein that extends inwardly slightly over half-way through the wall 99forming the bore 92, the transverse bore 122 thereby providingconnection for a fitting for a conduit hose 119 or the like (partiallyshown) extending to a uidic pressure supply (not shown) such as apressurized source of air, oil or water. Communication inwardly with thebore 122 is made by an unthreaded counterbore 111 which extends throughthe remainder of the wall 99 and communicates by way of a passage 121 inseal housing member 102 having the shape of an inverted L with anaperture 123 formed in the thickened portion of the ring member 90, thisaperture extending completely through the ring member to provide an airpassage to the cavity 89 which, as set out previously, is the spaceformed between the ring 90 and the main body 81 of the seal element 82.Thus, liuidic pressure may be imposed on the seal 92 and, because of thecompressive force of ring member 90 and seal bushing 112, when liuidicpressure is imposed thereon, the main body 81 of the seal member 82expands inwardly to tightly grasp bar stock 24 and provide an extremelyeffective seal therebetween. Outward leakage of cooling water from thefixture cooling chambers 14 and 16 from areas other than that adjacentthe sealing member 82 surrounding bar stock 24 is, of course, preventedby O-rings 98, 108 and 116.

The sealing means 80, just described, provides a water tight sealbetween the atmosphere and the fixture cooling chambers 14 and 16 andalso permits extension movement of the bar stock 24 when indexing isrequired. At this time liuidic pressure is removed from the seal 82 andits frictional grip on the bar stock 24 is removed. But, substantiallyno or very minimal leakage occurs at this time even though cooling waterand electrolyte solution are still fiowing in the fixture chambers 12,14 and 16 because an effective seal is still imposed between seal member82 and bar stock 24 due to the compressive force of the ring member 90and seal bushing 112.

Since various lengths of turbine blades or the like may be required tobe electrolytically machined from the bar stock 24, the extension 94containing the sealing means 80 is provided in a variety of lengths. Theproper length of extension 94, dependent upon the length of finishedblade, is then selected for attachment to the leftwardmost end of thefixture cooling chamber 14 to insure that the sealing means 80 envelopsand engages the periphery of the bar stock 24 between machined blades inan unmachined portion 25 thereof.

A pair of inner sealing means 124 (FIGS. l, 3, 4 and 6) are alsoprovided between the electrolyte containing chamber 12 and the fixturecooling chambers 14 and 16 to prevent the mixture of water andelectrolyte solution either in the electrolyte containing chamber 12 orin the iixture cooling chamber 14'and 16, respectively. Each of thesealing means 124 includes a seal member 82 and a ring member 90,exactly the same as previously described, disposed between theelectrolyte containing chamber 12 and the fixture cooling chambers 14and 16.

Each of the seal members 82 is prevented from inward movement towardsthe machining electrodes and 22 disposed within chamber 12 by abutmentagainst an insulating locating pad 126 of substantially flattened ovalshape in cross-section made of nylon or the like which, in turn, isprevented from inward movement by engagement with a flattened ovalshaped shoulder 127 formed in a guide means 128 for the `bar stock 24,the guide means 128 being provided in the electrolyte containing chamber12. An epoxy adhesive 130 disposed between a shoulder 129 of the guidemeans 128 and the locating pad 126 fixes the locating pad 126 to theguide means 128 and also aids in sealing the electrolyte containingchamber 12. A seal retainer 132, also made of nylon or the like andhaving an outer periphery of generally flattened oval shape, abutsagainst the outer side of seal 82 to prevent its outward movement. Thisseal retainer is seated in a -fiattened oval shaped bore 134 in theguide means 128 and is sealed therefrom by a pair of iiattened ovalshaped sealing rings 136, 136 so that there is no flow of the containedelectrolyte solution between the guide means 128 and seal retainer 132radially outwardly of the seal 82. As illustrated, the seal retainer 132is of sufiicient length to extend axially outwardly of the bore 134beyond the guide means 128 to abut by a shoulder 133 on the sealretainer 132 (FIG. 4) a seal retaining clamp 138. The seal retainingclamp 138 extends around and envelops the seal retainer 132 around acircumferential periphery 137 formed thereon and limits the sealretainer 132 against outward movement by a series of -bolts 139attaching it to the guide means 128.

Mounted outwardly of the seal retainer 132 and seal retaining clamp 138is a wedge seal member 140 made of insulating plastic which abuts withone of its faces the outer face of the seal retainer 132 and also abuts,on its opposite angled sloping face 142, an oppositely disposed angledsloping face 144 formed on the insulating wall 164 (shown onlyfragmentarily in FIG. 3), this sloping face being provided in a cutout145 (FIG. 1) in the insulating wall 164. The wedge seal member 140 isurged downwardly to move the seal member 82 into compressed positionagainst the locating pad 126 by a set screw 146. The set screw 146 isscrewingly engaged in a top plate 148 made of insulating plasticmaterial so as to abut against a face 141 formed by the termination of abore 143 in the wedge seal member 140 and urge it in the compressingdirection for the seal member 82.

Top plate 148 is mounted to the guide means 128 by being abutted againsta shoulder 150 formed in the guide means 128 near its end and seatsthereon on a flat face 151A formed in the guide means 128. Top plate 148is fixed to the guide means 128 by a series of bolts (not shown). By thearrangement just described, the sealing means 124 including the sealmember 82 and the ring member 90 completely seals the electrolytecontaining chamber 12 from the fixture cooling chambers 14 and 16,respectively, in the area surrounding the bar stock 24 and also providesfor movement of the bar stock 24 as indexing occurs by release offiuidic pressure upon the seal member 82 in the manner set forthpreviously in the description of sealing means 80, a pair of -bores 121and 125 and an aperture 123 in the guide means 124 and ring member 90,respectively, providing for entrance of the fiuid under pressure. Thebores 121 and 125 may take the form of the bores for entrance of liuidicpressure described previously for the sealing means 82. Such bores mayinclude enlarged threaded portions for attachment of ttings for ease inconduit connection.

The guide means 128 includes an upper supporting member 149 and a lowersupporting member 151 which, when viewed in assembled relation incross-section near their ends (FIG. 6), provide the guide means with arectangular configuration that generally encompasses the inner sealingmeans 124. A pair of thickened end portions 153, 153 and a pair ofthickened end portions 155, 155 are provided on the upper and lowersupporting members 149 and 151, respectively. These thickened endportions properly space the guide means 128 within the electrolytecontaining fixture chamber 12 by seating the guide means 128 inapertures 157 and 159 in the chamber walls 21 and 23 (FIG. 1). The endportions 153 and 155 are securely held together by 4bolts 147 (only twoshown) extending completely through the upper end portion 153 andscrewingly seating in the lower end portion 155. The end portions 153and 155 terminate inwardly slightly beyond the locating pads 126 so thatow of electrolyte adjacent the electrodes 20 and 22 is unimpeded bytheir mass.

Disposed between the end portions 155 and 155 on the lower supportingmember 151 (FIG. 9) are a series of stringer members 161, 163 and 167.The stringer members 161 and 163 are generally rectangular incrosssection and provide support and rigidity to the guide means 128. Infurtherance of this aim, these members may be integral with or welded tothe end portions 155, 155. The stringerY member 167 is also fxedlyattached to the end lportions 155, 155 and is generally rectangular incross-section at its upper portion but has a tapered bottom portion 171so that electrolyte solution streaming upwardly through an inlet means45 provided between the stringer members 161, 167 and 163, 167 is notseverely impeded in its flow and the turbulance thereof controlled.Stringer member 167 also mounts on its upper side a guide channel 176(FIG. 7) serving as a lower guide and alignment means for the bar stock24 as it traverses the electrolyte containing fixture chamber 12.

Disposed axially intermediate the widths of the thickened end portions153 and 153 of the upper supporting member 149 and extending between theend portions is a single stringer member 178 which may be made integralwith or welded to the end portions 153 and 153 to provide structuralrigidity to the upper supporting member 149. Stringer member 178, asstringer member 167, also supports a guide channel 176, this guidechannel serving as an upper guide and alignment means for the bar stock24 as it traverses the electrolyte containing fixture chamber 12.Because of the absence of structure on opposite sides of the stringermember 178 an outlet means 47 is formed on ropposite sides of thestringer member to provide for outward flow of the electrolyte solutionand thereby removal of this solution from the area adjacent theelectrodes 20 and 22.

The guide channels 176 and 176 are made of an insulating plastic and aregenerally U-shaped in end view and cross-section to provide for propertracking of the bar stock 24 as it traverses therealong. These guidechannels extend linearly along the full length of the stringer members167 and 178 and also extend outwardly beyond the stringer members so asto enter and be seated in the locating pads 126, 126 (FIG. 8). A pair ofupper and lower apertures 182 and 184 are formed in each of the locatingpads 126, 126 for this purpose. Thus, the guide channels 176, 176 areconstrained from movement transverse to the linear extent of theremainder of the guide means 128 by the locating pads 126, linearmovement of the guide channels 176, 176 in the direction of the barstock 24 being prevented by abutment of the ends of the guide channels176, 176 with the seal members 82, 82 of the inner sealing means.

lt should be apparent that the guiding means 128 just described providesa positive support and alignment meansand an insulating means for thebar stock 24 in its movement through the electrolyte containing fixturechamber l2 while still affording an nnimpeded area between tlie stringermembers of the upper and lower supporting members 149 and 151 (the areabetween stringer members 161 and 178 and the area between stringermembers 163 and 178, respectively) for the movement of the electrodes 20and 22 inwardly towards the bar stock 24. Convenient inlet and outletmeans comprising the before mentioned inlet 45 and outlet 47 are alsoformed by the spacing of these stringer members to permit the flow ofelectrolyte to be directly impinged n the work area of the bar stock 24adjacent the electrodes and 22.

Since the bar stock 24 in the area of the inner sealing means 124, 124is conducting a high fiow rate of electrical current, entrance of thecooling water flow through fixture chambers 14 and 16 is adjacent eachof the sealing means 124, 124 to prevent burning of the bar under thesealing means where no cooling can be done. Cooling water flows to thearea adjacent the sealing means 124 through a pipe or conduit (notshown) which is conveniently attached to a conveniently internallythreaded flange 156 fixed by epoxy or the like to the top plate 148.Flange 156 communicates with a bore 158 extending through the top plate148, the said bore being angled outwardly and upwardly to providesufficient peripheral area on the top plate 148 for attachment of theflange 156. Communicating with the bore 158 in the top plate 148 is abore 160 extending through the upper wall 149 of the guide means 128,the said bore 160 being placed in confluent relationship with the bore158. This bore, in turn, communicates with an annular groove 162 in theseal retainer 132 with the groove 162 extending 360 around the sealretainer 132 to serve as a distributing passageway for the inward ow ofcooling water.

A plurality of channels 164 in the seal retainer 132 communicate -withthe annular groove 162 and extend angularly inwardly therefrom toprovide a flow of cooling water which impinges against bar stock 24immediately adjacent the inner sealing means 124 and then flowsoutwardly around the bar stock 24 (FIG. 1) into its respective fixturecooling chamber 14 or 16. Outward liow therefrom, as set out previously,is through outlet pipes 76 and 78.

The cooling water fiowing adjacent to the inner sealing means 124, 124is not at the potential of the electrolyte containing chamber 12 but iskept at the fixture cooling chamber potential 14 or 16 because of theisolation afforded by the various members of the sealing means 124having insulating properties. Also, additional insulation in the form ofthe insulating walls 164 are disposed against opposite sides of thefixture electrolyte containing chamber 12 and between it and the fixturecooling chambers 14 and 16 to insure that the fixture cooling chambers14 and 16 remain at their own potential.

Each of the insulating walls 164 (FIG. 1) is fixed by an epoxy resin 165or the like to the wall 35 of its respective fixture cooling chamber andcovers substantially the entire surface confronting the electrolytecontaining chamber 12, the ends of the insulating wall 164 nestingagainst shoulders formed on the confronting chambers. By the insulatingarrangement of the inner sealing means 124 and glass wall 164 no errantelectrical current flows between the electrolyte containing chamber 12and the fixture cooling chambers 14 and 16 and all current flowingoutwardly from the electrolyte containing chamber 12 is constrained toflow within the bar stock 24.

Means is provided for indexing the bar stock, this means being showngenerally schematically at 166 and being conventional in character so asto provide movement of the bar stock 24 a desired amount upon actuationto provide an unmachined portion within the electrolyte containingchamber 12, the index modulus selected also locating an unmachinedportion of bar stock 24 within the inner sealing means 124 and 124. Thisunmachined portion, of course, is also of sufficient length for formingthe desired size of turbine blade or the like.

The fixture cooling chambers 14 and 16 are completed by an access port168, generally conventional in character, mounted on the wall 30 over anopening 171 therein. The access port 168 includes a viewing station 169,rectangular in shape, and made of translucent material and held in waterhight relation to the wall 30 by a rectangular flange 170 mounted, inturn, to the wall 30 by a plurality of -bolts 172.

A single embodiment of this invention has been shown and described andit is readily apparent that many changes may be made therein withoutdeparting from the scope of this invention vas defined in the followingclaims.

What is claimed is:

1. A fixturing for the electrolytic machining of elongated stockmaterial comprising in combination; (a) an electrolytic chamber forcontaining an electrolytic solution under pressure, (b) said chamberhaving a plurality of walls with at least one of said walls having afirst opening therein for receiving the elongated stock material with afirst portion of the material disposed in said chamber and a secondportion of thematerial projecting beyond said one wall, (c) a cathodeelectrode disposed in said chamber for electrolytically machining thefirst portion of the elongated stock material and including meansmounting said electrode for movement relative to said chamber and towardthe stock material, (d) a cooling chamber for containing a coolingliquid and being disposed adjacent t0 said one wall and connected tosaid electrolyte chamber, (e) said cooling chamber having an openingtherein aligned and conuent with said first opening for receiving thestock material with the second portion of the material disposed in saidcooling chamber, (f) anode electrode means disposed in said coolingchamber for conductively contacting the second portion of the elongatedstock material, and (g) sealing means carried by at least one of saidchambers for sealingly engaging the portion of the stock materialintermediate the first and second portions thereof and for sealing theopenings in said chambers from each other, (h) said sealing means havingan opening therein for receiving the intermediate portion of the stockmaterial and being alternately expansible and retractable in response toa fluidic pressure being imposed thereon and withdrawn therefrom,respectively, for alternately sealingly engaging and disengaging theintermediate portion of the stock material.

2. The combination set out in claim 1 wherein said sealing meansincludes; (a) a resilient seal member having a deformable outerperiphery, said seal member having a deformable inner periphery forcircumferentially surrounding the intermediate portion of the elongatedstock material and sealingly engaging the same, and (b) meanscompressingly engaging said seal member adjacent its outer periphery forlimiting the outwardly expanding movement thereof.

3. The combination set out in claim 2 wherein said sealing meansincludes means for compressing said seal member axially. (a) anelectrolyte chamber for containing an electrolyte under pressure and forreceiving a rst portion of the stock material and having cathodeelectrode means disposed therein and means for moving said electroderelative to said chamber and toward said stock material, (b) supportmeans disposed within said electrolyte chamber for guiding and aligningthe first portion of the elongated stock material, said support meanshaving provision for the entrance of said cathode electrode means forelectrolytically machining a portion of the elongated stock material,(c) a first and a second cooling chamber for containing a cooling liquidand for containing second portions of the stock material and beingdisposed on opposite sides of said electrolyte chamber, said chambershaving aligned apertures therein for receiving the stock material, (d)anode electrode means disposed in said cooling chambers for conductivelycontacting the second portions of the elongated stock material, and (e)sealing means carried by one of said first 1 1 cooling chamber and saidelectrolyte chamber and carried by one of said second cooling chamberand said electrolyte chamber for sealingly engaging said chambercarrying the same and for sealingly engaging the stock material, saidsealing means Ibeing expandible by uidic pressure for providing apositive seal ibetween said chambers.

4. A xturing apparatus for electrolytic machining of elongated stockmaterial comprising in combination; (a) an electrolyte chamber forcontaining an electrolyte under pressure and for receiving a rst portionof the stock material and having cathode electrode means disposedtherein and means for moving said electrode relative to said chamber andtoward said stock material, (b) support means disposed within saidelectrolyte chamber for guiding and aligning the first portion of theelongated stock material, said support means having provision for theentrance of said cathode electrode means for electrolytically machininga portion of the elongated stock material, (c) a lirst and a secondcooling chamber for containing a cooling liquid and for containingsecond portions of the stock material and bein disposed on oppositesides of said electrolyte chamber, said chambers having alignedapertures therein for receiving the stock material, (d) anode electrodemeans disposed in said cooling chambers for conductively contacting thesecond portions of the elongated stock material, and (e) sealing meanscarried by one of said first cooling chamber and said electrolytechamber and carried by one of said second cooling chamber and saidelectrolyte chamber for sealingly engaging said chamber carrying thesame and for sealingly engaging the stock material, asid sealing meansfor being expandible by tluidio pressure for providing a positive sealbetween said chamber.

5. A ixturing apparatus for the electrolytic machining of elongatedstock material comprising in combination;

(a) an electrolyte chamber for containing a first portion kof the stockmaterial and an electrolyte under pressure and having cathode electrodemeans disposed therein and means for moving said electrode means towardthe stock material (b) a cooling chamber disposed adjacent saidelectrolyte chamber for containing a cooling liquid and for containing asecond portion of the stock material, (c) electrode means contained insaid cooling chamber for conductively contacting the second portion ofthe Stock material, (d) common wall means forming the adjacent portionsof said chambers and having an aperture therein for receiving the stockmaterial, (e) sealing means disposed between said cooling chamber andsaid electrolyte chamber and disposed in said aperture means forsealingly engaging said wall means and the stock material, and (f)insulating means including at least a portion of said wall means and aportion of said sealing means for insulating said cooling chamber fromsaid electrolyte chamber, said insulating means being interposed betweensaid electrolyte chamber and said cooling chamber whereby the elongatedstock material provides the sole electrical path therebetween.

References Cited UNITED STATES PATENTS 2,725,352 1l/1955 Strobel204-211X 2,756,206 7/1956 Rosenqvist 204-225X 3,296,114 1/1967 Lloyd204-225X JOHN H. MACK, Primary Examiner D. R. VALENTINE, AssistantExaminer U.S. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Parent No. 3 554,892 Dated January l2, 1971 Invented@ Eugene P Schellens et al It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 10 line 58 beginning with (a) an electrolyte chamber" cancel allto and including "between said chambers in line 7 column 11 same column1l line 32 "asid" should read said Column 12 line 8 after (c) insertanode Signed and sealed this 29th d ay of June 1971 (SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting OfficerCommissioner of Patents FORM IDO-1050 [IO-69) UscoMM-DC 60376-P

